What do carrageenan and agar have in common?
Question 1: Think about the chemical structure of carrageenan and agar - what do they have in common?
Answer: Carrageenan has a long chian of galactose residues linkage, giving it a high molecular weight. Carrageenan is composed of linear galactan polysaccharides. Agar has similar structure as carrageenan. Agar is a polysaccharide derived from red algae, which contains sulfated galactose monomers.
Question 2: What are the differences between kappa, iota and lambda carrageenan? Why?
Answer:
Repeating Unit:
Lambda: D-Galactose-2-Sulphate and D-Galactose-2, 6-Disulphate is the repeating unit.
Kappa: D-Galactose-4-Sulphate linked with 3, 6-anhydrous-D-Galactose is the repeating unit.
Iota: D-Galactose-4 Sulphate linked with 3, 6-anhydrous-D-Galactose-2-Sulphate is the repeating unit.
Question 1: Think about the chemical structure of carrageenan and agar - what do they have in common?
Answer: Carrageenan has a long chian of galactose residues linkage, giving it a high molecular weight. Carrageenan is composed of linear galactan polysaccharides. Agar has similar structure as carrageenan. Agar is a polysaccharide derived from red algae, which contains sulfated galactose monomers.
Question 2: What are the differences between kappa, iota and lambda carrageenan? Why?
Answer:
Repeating Unit:
Lambda: D-Galactose-2-Sulphate and D-Galactose-2, 6-Disulphate is the repeating unit.
Kappa: D-Galactose-4-Sulphate linked with 3, 6-anhydrous-D-Galactose is the repeating unit.
Iota: D-Galactose-4 Sulphate linked with 3, 6-anhydrous-D-Galactose-2-Sulphate is the repeating unit.
Solubility:
Lambda: Very soluble in cold water.
Kappa: Dissolves only slightly in cold water.
Iota: Needs to be heated to be soluble in water.